SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd18142479d946d0a0e1c9aba7eba31096f3294a3351b5a22c1cf0c22c015455a' 
  AND token = 'i41sJLlQ9ine7+/P2GVsQESzQTDZP5oUM5GhZteB250=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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