SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10953576830541184bb9669a78142b11619fd3524293e27fd7da561df139ce20' 
  AND token = '5kxpOB+F6HWbkkbb06XZVCKfyZkDHuDGwQ6uQkCs6XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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