SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c5a0511223ab41e11323490ae987599c4c950a0b981afa1361a59b57bc5de78' 
  AND token = 'F4WFAdeSUc9Y3cbmtpACmJngc+lWV0LkMuFnksX21l8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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