SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b30f0c7b44d493ed5b75e7ecd710affd914511ce738feb564d7c51512e65622' 
  AND token = 'zQs3NUhw5gKEcvsnUwoXdCApfgvB8hdTf4qgboQIHy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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