SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afbb20e3ea388fa887dbeb27684e588edb68ae2f2c3decb17f5d46a249ff34a5' 
  AND token = 'qID+ISznLZLZ0AGTEm2iI6Mr8EV3Ycrs4pfaBeSSOoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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