SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8288925374d2060231b92458dcd6427549cdeaf16d9298aec336a7429ba9db6b' 
  AND token = 'EWbaMvvpRg7fwDzp0Ltfj4sgqbPb6Zl7PH6yYjDiUa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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