SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45b3c73a4274242ab4a3e14b71cdc75c556be05d3928e786e351381135844417' 
  AND token = '9QkRY0embZdEbCt5ogfHHtamcZ9JnOhXK3In39P4vOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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