SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da14cf6fe4a2929319e3fe58c33431395f634189e42370bd079acbc51b405e2e' 
  AND token = 'EjIlNAHiD9ZbLe5w9xrNJkS4sAmhad/H7Avh/HQ4tgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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