SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587532ef0e88e8c6f0b2043446915be8907328fca91edeb3753dd234ca8fcdbc' 
  AND token = 'xQLAuE9Jw8uaESQOARKAhS5HQt16ru/eG3Kxx6L+Sao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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