SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a7994289040e088abbf9b1256afa822dae4b543f588f68007126c6b71d73286' 
  AND token = 'gHVecFm9zpT8EUe3BOZnTerk+wGlP9dGNS/HrDR211A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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