SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f611c0ce0db6561839cb42edf2ee50637b8cec957fafa8ffa9fc1f885cf061e9' 
  AND token = 'sJ5YcwJTPmOAOrg6d530QF5Ec7XeIVx5HPwstako/pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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