SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e1d9117dc12a0c6c8f6601354f4db48b79b18543f83dcee60ecadaeede14307' 
  AND token = 'cJIMvOKR/4Mp3iLBfV2SYlx2XPgwXTpCgTngtPq44Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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