SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '859ffd8625818d4b4b4eadba8f8b05d804f0a92217b67847f356cd2b2d480e8b' 
  AND token = 'W4FRU8Xxc1z7ak3pfJAIMwLD+dkL05d7SbiGBFUoM1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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