SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a08f97cb89411908cf06a54b3777f4b1225493bc174423262c56e106bda093a' 
  AND token = 'PR3RhnGvpNMlUH4ECYOgyvb115rqglhWFZ9U0K1wuMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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