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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac6783ce9dd0e971ffb9ca320825eb7be42caf33ce18bb28fe6d1176f9b6a55a' 
  AND token = 'hTiM1w+tT4AYIt50lcnqe6UCf/NHWwfFrsxUdVebJYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}