SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20f70fb8b880e32a2a00cdcbe64397e62b261c9280870d3d5e3f9495875d2e4a' 
  AND token = 'K1qkLyMH8Eaocp37w229lx5Vb/19kIdCkqsl0T5UulY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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