SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41aecb950c67faedabc510f1970b91909dfa391eca930c4c368fd1de04db6b0' 
  AND token = 'oF5+JNCXlN9VzGcOJrbIqyo2qPgLtt1XYyFXOAoSGVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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