SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4877fe69727534bd2d88c8b95c5afca8ee1a5e146918cd18d1381184baaeff7b' 
  AND token = 'eZb1gC2EJJoIwe9uHKkczBMnNAs4qfd4x/6pG4KbVzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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