SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfcaef8aa3484c0527814f182854e944d8b555c3989f88571dbe69dcab25f3b4' 
  AND token = 'LR80MDH4yjedZI1hn5mktBvuN6REss2g5PHoVscdSEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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