SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f577395ba91dbf1664a6a340511a0c69495c487f8c2da3bfd3deea689473f29' 
  AND token = '89isO5WtWtiJxe3ben9x/DEYm6iYMs72za88EBpCL7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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