SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1eb8bf3df1dde1cfdf7b7b583f37161683d5247d3e3b54e5013352b5d40e9fed' 
  AND token = 'eh+1up52nkvMvCS4yQDA+nIMGc0GD2PmwrNvzVSkei8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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