SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd84824978ef276b168c77ae89c20b6e5d6f8526472e4017e48600cca8506f4c' 
  AND token = 'ATEimr+CfUQVLUKt2MsdayXtujcLu4D+Q2xye7hMPyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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