SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47d877b5d70f0514ddf1af512357702db375b6ccbb74b5426b524f75bb947eba' 
  AND token = 'Cpm2KVBw2YQPOwZ8q2IRDVXA3ZqSyNzV40j+ogLQDT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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