SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9a676638469d5c27df427debcdfd6cbaeaa40436cd71f42cee935855da258eb' 
  AND token = '1+W8Kl9BU1Pwbt1/KHN8Ry6x6bLHdEQPFKahQZT2R04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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