SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b05e988db1bbc2289ee718a09178568fcae016d1c868a561da1ca88b41485429' 
  AND token = 'nh8aJiQISkAnMNPbcw2ehWqFrYhZ4TaPKIQsCm6vJdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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