SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69fc50dee5ada6cffa07394a2d9df9dc00f858192215432dae1204eada36dd5e' 
  AND token = 'b53uy0WYaPaC41wGzFBUyw02fg9iYBPfsB49YOh48ZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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