SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c994040637f472a1d17d669fbba88b2a416b34ddaf83e0895f2adc4608e5a925' 
  AND token = 'OdjVlsoYfR2/TYGGA7erlzBj9lXlsPJhKhW0613UUE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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