SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e9a20caf64788111ac7535fbf33e760131ec5c05603171c850126f8e36c831e6' 
  AND token = 'gR1Nq69l9ocy4BfXg3tRJ1T22BUeF5ifbOWolINWWOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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