SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a3a6538daf8594f131b4eda4f2c170ea098b0e629345ab85617838b963e7158' 
  AND token = 'oUfTPMvlN3mbWqyosWCWC9nU3Sh1Ok8+bA1OPy0wNLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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