SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b082a95820b8b2d1737a9e384db8309a7e2782bd81a42b5ffc664695a6abfcd' 
  AND token = 'PKbNLipAzsrDiWjbJpODEHwxMF2tSNJYgz6R0cG/kYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}