SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ed71cab1056b270691c59c8e4c6c872a434a5282dfd4ec1b3d571f39c84343' 
  AND token = 'npTQ9ukjagpQwEmWiXDKhaiJRJBcxv7incKd088Sakk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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