SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0768123fb8f96ab56d338ed64433b90524ed8c87777f936070bc1568f9dcdea' 
  AND token = 'enUToGHv11rdR++JzTLZPnXME7LwTtXGbeFD2DlY50g=' 
  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