SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c28547da596d39e3428e37a3da671a4c5b87a983b4c5683430740f05ec48c4e6' 
  AND token = '7Kuqb6yvteR/b0BsZoMarz0IumJOWLxhB9bLNT5zk6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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