SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '21cfba2230d6402d0744f8252036b7bf40b05053e4f069cc895e6ac073b3b4e3' 
  AND token = 'KBizG8bkNakJilYopx8fBPnp3j3ABVZdFI1t02aXR5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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