SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd70e274097af55c55373f8dca38ad78aa7efc00dd3994bdea7f59fa211a2ac47' 
  AND token = 'psvbWnbkpJ5AeJgoaEik7rpPtW1BsBNR2MNZYUoQnAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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