SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ba51cc42a8f91934cb9783f12e592d46ee14dee4702d6738f98e7e093beac48' 
  AND token = 'zDHx+6O1aLhB5eXijcHVylsmvYz7IlRWytsFQ8P9RNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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