SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cc88831853a362af583910e0a2def66ecab9f6be1681db57635c0d5de8cb503' 
  AND token = '+F+7uv9yWMo/IguSWFWEjwit4+0KUM0E7ssDlXM5Pkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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