SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56e02296531f1f4b6560d3240b58304b0a4d9d26e9571d00298a45a63317bbd8' 
  AND token = 'Ez48KyvZTBZqmeYBoyJbHgVZ7tTho/t7kPQhQKlYlJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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