SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2dbbf7057781da217bbad3748cb7e54635badcfa3f8b9fcc2c91f6640fef72a' 
  AND token = 'qP7GQOtmph8cHzwU1dLot+lnoUPtMKlbwBjOmr1EWDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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