SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c7c343a3c24fa756934f61da2b3d61ab271b9f859eed3da38ac32d867aab291' 
  AND token = 'wzVRN/xaytJpMwE4MCHL/2qCUMjUER46ImPFyvagRZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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