SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c331b7515d9e267ee7f48e973d532cd4485ab803c81becfdcb046739f2a57499' 
  AND token = '3V244zCB7RGb3cCzXJr+c7hhBT/gIZAQTbDYOVfWySg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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