SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6270a3e2d4df4e5eaf372d6478e54e5c078b8c5ab51a3f3b681a1730682dfcdb' 
  AND token = 'uu/XYnK1sHG+ilHRMQKu+iHuvh96Q1nyfPZ8A0spnLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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