SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f3407b3014f14cba76e87ffc1ff61d688a34880026d8e29521f769fc336e746' 
  AND token = 'Ew5wiap1wEXn5Dtq6UevFt3ntLSQPvhXPJFtwCxyaOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}