SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b248935076d0390cf83edef58dd4a34a364859ddd6b3b8c6b6f3056cd131c85e' 
  AND token = 'D6dqoQlY62kj/LEs4vuX41GVND38Lx/BESvqD5iSBnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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