SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c741c9edb3fc8160b182f76f56b28e4955168167e9d413c3a365759c2464f699' 
  AND token = 'zZtCuMDxBao7Xz+rYD5D8JkvtXGaeHuNbOWq85ab+iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}