SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e458f06a3964f5bb75204147445da8100e3574c254374689d7fab94cc87bcf' 
  AND token = 'cOIisUjmccLZwCov1B3Ouk2OeRzwWfgk5kqyRbkxa14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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