SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9d33c90aa085a4c6baddac1cfb77ff45e5afe25b738abcbfaccc30588d077c4' 
  AND token = '2bVyDihaiIYEod3154BomFkQPaogQappxBSkWPcVBjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}