SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec6340d5f4468ebadb9f7020cdf7487a467bb4692a2407dc8f9d74e2121358e6' 
  AND token = 'oSmxa7xd3iBfwIZfWFrHTuytd4b+5oxTU32BaG7/fag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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