SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '511c84ce825569017e044a318f70a7db543ba80d6a32485b2f43fb36ff5806f5' 
  AND token = 'URwqmiNbHmLgb4OSR43Lh7Yjd7AXLgCvZwwsZy7qauo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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