SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c983898d24559f355fea29e13a0cfbff808ff50c189205847cb9f3064326bd79' 
  AND token = 'SHQeDbT9wWJJ0G5uUj6SpsqVQNercQUYfRqhryNRVIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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