SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10eb8dc5817e3dc7b38e45cdf5bdcc176bf52f0e152cc940d83d6037af1ebc28' 
  AND token = '6Lh1Oa5GBsIVKf2vL5g5L+CpVUWsEraOatiwI45vryY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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