SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '474c21acac649a19d22eeef44f3288d554d160534fa1047e963415879b2c2800' 
  AND token = 'NQvxvpTnYOsDsq19pdgVuAzBmTFJPywIe7pN5CzfwJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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