SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b718b54bfd3032eb6ad1e5d4051759cc0596415c3ad83328adc8fdb01ea20ee' 
  AND token = 'ZJpQHCMXp/Y5NxPQn3f9QL8o6Kj9e9LSGp9Vh4cMTlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

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