SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0e63b03c662db269fd2b6e6abe653d08570d75ade3148566b21216b493031f' 
  AND token = 'Oimo8zlx5f7k814jJmiGkXVtHnLljpzAVrRozYZ5aZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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