SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd236348b4473eb963e6199c1928b51de51b7b9ff7599b8ae3c62e59d49d9109b' 
  AND token = '6LJGkKQITC34YFlDPYlxxsOjWkg/5Yk6A7BmNgGovLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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