SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fff85755fabc5ed2871df63b2dfe1bf4ddd4b3cd42ba474b393296ac7166a9bd' 
  AND token = 'l0Jn1MhSBzl69XoHqEQp2ccvGBgEqeKiyjQ7TH2uP8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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