SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7d24f93a9f2147e1639b30ce1f14295ea9931dd2e2eb376d03918d3f8cc0991' 
  AND token = 'xCLbsIEIg+q1KtXMK3fOoxpRP5w6eHSEEXLrFxulYGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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