SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc51e6636a8bece0ac95be621e0ccf4064087644e6b7b13df09aad3ff48f8ced' 
  AND token = 'w6CnrLP73huc8bWe5R+t84USnhjtxDiUQetNRR9MdWA=' 
  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