SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1607a23c1cfaf8a8e9e9237820f6e246b6a42d5453df5ab285ae87bdf12af275' 
  AND token = 'JQfzJuh3ygn9UmhYJv6tAx3A5gyZotIheoHT7VljGhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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