SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '861104172edf82e0826272210e77814fb599c3c1dce1dff4939e29590f3ed8bb' 
  AND token = 'CKXT0VBRNrLiyWteLF5dH2brv97XVbTx3NXnN+ddj9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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