SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3e47b574374bbb64d3b1b62f8ec015b703a57c72f9051db177197cb4e8916db' 
  AND token = '0MPijy132Hcf8FleMssWgIsUOGAkR+JcAYU4dX/EywY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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