SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd517d84e8c3f0dc8e03aa6b91ecf59a194240c12a743d2b2d171eae061174993' 
  AND token = 'ZmMYqzQ8YyeMBShgGJydyqQTK3FnKt/2SQBOgjf6nMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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