SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd90e6908f2ad1787267a5bce7578231aedef5a9912fdf11d92f624408dab463' 
  AND token = 'jO1xm3HibKavJ1+3KKV/SmnW5Z93fJ5gjzOiS9CljKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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