SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daa09a6b985102f8339373f763f7d5dcc3684bcd9b53e2475cca6f71d1e422bc' 
  AND token = 'I2GTPDD9+/PYibLaBrWRV3kbY55ZCmLDn4GTtxzZwJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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