SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f391b416a922f50bfd4848519fdeb8a75000387b6eb47e8674261197bdd6b58' 
  AND token = '8xZbA+AK1djjWUindu8TBeKR5j5zQX5IQ6Om6fBw8NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

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