SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e380f12add0bab8e73afc506df59d9c02d08d80fe1d870c769eb67d33f4d688' 
  AND token = 'Oe7Dhs5B8nAbdmGZqp5I9Mpvly31jjI2lY1Tst4wFVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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