SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd54f817ee635e81c3cc3134bd63c8b16798f6639622b6e9c54be01cfb03b8005' 
  AND token = 'p2Paw3Whey2hrs4EfXgsso4kBwb4fTMf0Ttw56Siep0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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