SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb500ab4c232b1b86842a413b47da1f797f3f0f96d49ff97c0d8404cef5ca07' 
  AND token = 'K288UIO1YaHPiYjpkYJJf/305jLwcgdVrHmLLgLcx9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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