SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '547884c47983b07ca35321afd0b426ef54d219a1a35d6869b5eb683202263eb8' 
  AND token = 'PZ73L7OV1DPLcWasezYcu5KPwXU5jQhX9jihA9UBlYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables