SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e9c5b4e4dd18b312440974fb745a8cecb09db73dc44e6569d6617de7d58c5b09' 
  AND token = 'to6IhBII/3rkXGQAHiFxVg2lBK2DBkv3Bjl6gQ4AwgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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