SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffab9b00f7f51302e83fa5f5740927e3e2ad64f96997e34a98308960ad7da993' 
  AND token = 'KD93MfUlIU2TCQ+H3TozApGMWFpTOi4ryogy7q6S4u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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