SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1984d351b06f2d0147b5cf742cfac00f84a48ad65cb8afe817b8ba4c241e11b5' 
  AND token = 'XPDCQiYNjGUJ1ndtoqRmakesgsYPjDiq8w1ytJ7//Oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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