SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3f8f5733050e4cb7bff053840445326ba0c78a3998599359fd84ddf96d49636' 
  AND token = 'GnSxpFOHq565fOaKUXQR/gNsFUXVHU2QmIrTSY/aaCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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