SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '330d75a03c5eba1d35cb140d159e26e0dfab2245b956054af7e495d818baadd4' 
  AND token = 'ZR2I2gtvordvKNPv5WLXkF/0gFdKy5wjXOjN7MW4Faw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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